Latch mechanism for collapsible shelves and doors.



C. DE VLEESCHOUWER LJ. TACOIVAl `LATCH MECHANISM FOR COLLAPSIBLE SHELVES AND DOORS.

APPLICATION FILED JULY 23| 1914.

r Patented Jan. 30, 1917.

l Q @im n h@ thereon CAMILLE DE VLEESCHOUWER AND J OI-INN ES TACOMA, 0F AMSTERDAM, NETHER- LAMES.

'LATCH MECHANISM FOR COLLASIBLE SPEELVES ANI) DOORS.

Specification of Letters :Patent Patented Jan. 30, it?.

Application filed July 23, 1914. Serial No. 852,628.

To all ywho/m. may concern:

Be it known that we, CAMILLE nn VLEE- scnonwnn and JOHANNES TACoMA, subjects of the Queen of the Netherlands, the former residing at Amstelveensche `Weg 189, and the latter residing at Nieuwe Zij ds Voorburgwal 227, both inAmsterdam, in the Kingdom Ot' the Netherlands, have invented certain new and useful improvements in Latch Mechanism for Collapsible Shelves and Doors, ot which the Jfollowing is a specification, ret'- erenee being had to the drawings hereto annexed and to the figures and letters marked that is to say:

rlhe present invention relates to latch mechanisms and particularly to mechanisms for automatically securing doors, collapsible shelves, typewriter-supporting boards for desks, and the like, when brought into a jnedetermined position.

The primary object of the invention is to provide'a latch mechanism which will automatically secure and sustain the supporting board` orV the like when it has been moved to a point jnst past its operative position and has then been returned to operative position, but which will release the supporting board when it has subsequently been moved away from its operative position in the same direction as in the first instance but to a greater extent, so that upon movement thereafter toward its inoperative position the board will be tree from obstruction by the latch mechanism. v

The improved device is shown in the accompanying drawings, in which:

Figure l is a perspective view of a portion of a typewriter cabinet or desk and a portion of the supporting board for a dis appearing typewriting machine, the board being shown partly in section and the improved latch mechanism being shown mounted upon the cabinet and operatively engaged with the supporting board, the board being at the limit of its initial movement past its operative position; and, Fig. 2 is a similar View, showing the relative positions of the different parts of the latch mechanism when 'the supporting board has been lowered into its operative position after the initial movement thereof, the limiting member being in its inoperative position, the locking pawl being iii-operative engagement with the supporting board, and the sliding piece carried by the locking pawl being locked in its retracted position.

rl`he lock mechanism is composed of the main parts A, B, C, D, E, F, and G. lOne of these devices is placed on the post 26 on each side of the case.

rthe sector A is pivotally mounted at al, its rotation being limited by the pin a3 and the slot a2. 0n its outer lower edge, a notch or groove a is provided into which the pin b1 of one arm ot' the bell crank lever Bj, which is pivotally mounted at b2, catches. The second arm 3 of this lever B is conn'ected by means of a connecting rod C, to a sliding piece D, said rod C being connected to a side projection da of this sliding piece D. The sliding piece D is guided by two pins el, e2 which engage the slots d1, Z2 respectively, so that the sliding piece D can move in a straight line relatively to the arm or locking pawl E, on which the pins e1 e2 are fastened. T he sliding piece D moreover possesses at its lower end a hook or pawl d5. The head (Z4 and the hook or pawl d5 of the sliding piece D are arranged in a straight line with the guiding slots d1, d2. Finally, a lspiral spring d is attached to the side projection d3, which spring is fastened at its upper end to the locking pawl E at e3. This locking paw] E pivots about the journal e* and is continuously drawn by a spiral spring e5 against the two pins (Il, g2, of the disk (l. For this purpose, the upper portion otl the locking pawl E is provided with two straight bearing surfaces e", e7, which correspond to the pins g1, y2. The turning of the locking pawl E is also limited by a slot c and a pin e8. y i

Opposite the hook or pawl d5 ofv tlie sliding piece D, a spring-controlled pawil F is arranged, which, being subject to the pressure oi' the spring f2, tends to turn around the journal f1 in a counter clockwisedirec tion, being limited in this turning by a fixed stop ,'F. The disk G which carries two pins (/1, ,f/t' is pivotally mounted on the fixed journal 1f/3 and said disk G is formed with a head g, which in the position of rest of the lock mechanism is situated above the head et' the sliding piece D. y

On each sidev of the supporting` board 2 to be locked, there is a, catch or stop 24, which acts in' connection with the head dof the lock mechanism. During the upward supporting board 2 is limited by the sector4 movement of the supportin board 2, the catch or stop 24 strikes the side of the head d* which yields sidewise, and as soon as the stop 24 has passed, snaps back into its original position under the pressure of the spring e5. The upward movement ot the A-in the position shown in Fig. l. if, either by the eier-tion of slight pressure on the supporting board of the machine, or by any means, the board 2 with its catch or stop 24 is now slightly lowered, the said catch carries down with it the sliding piece 4D and the hook or pawl d5 catches in the corresponding hook of the pawl F.

When the hook (Z5 has once caught in the pawl F, no further downward movement of the board is possible, as the head d4 cannot move out of the path oitI the catch 24, as the pins e1 and e2 .are at the top of the slots all, d2, and thusl prevent the sliding piece D from moving farther downward. The board 42 is thus securedl in the position shown in Fig. 2. The slight sinking of the supporting' board 2, and the downward motion, thereby produced, of the sliding piece D over the guiding pins e1, c2 in the slots 031, cl2 is transmitted by the rod C to the bell .crank lever B, which consequently turns in a clockwise direction and carries the sector A aroundito the right, so that this is drawn back out of the-path of the supporting board 2, and no longer limits this in its upward motion.

1f it is desired to return the board, all thatv is necessary is to raise ythe supporting board 2 slightly, so that it passes the sector A, which is drawn back sidewise, and the catch or stop 24 strikes the under side of the head g4 of the disk G, turns the latter around' the journal g3, Iand moves beyond the head g4.

As soon as the catch or stop 24 has passed by the head g4, the disk Gr is turned'back' vagain. toward the left by the action of the spring e5, transmitted by the bearing surfacet7 to the pin g2, so that the head g"l is below' the catch or stop 24. When the supporting board 2 is lowered again, the head g4 is turned downward bythe catch or stop`24, the pin g1 through contact with the-bearing surface e swinging the arm vE out to such an extent that the hook Z5 is lifted out of the pawl F. But as soon as this is released, the sliding piece D moves upward by the action of the springd until the upper edge of the head d4 is above the catch or stopl 24, so that the latter with the supporting board may move farther down unhindered. As the sector A is swung again toward the lett hv the -snapping back of the sliding piece D,

al1 the parts of the lock mechanism are once more in the initial position (Fig. l).

Having now particularly described and ascertained the nature of the said invention Laie-,oie

.engage a part of the supporting member after initial movement of the same past its operative position to a certain extent, means for limiting the movement of the supportingl member in this direction normally to the extent mentioned, means for rendering the said limiting means inoperative upon return of the supporting member to Operative position, and means adapted to be actuated by the said member after movement of the same for a second time and to a greater extent in the same direction past operative position and upon return movement thereof ormoving the locking pawl into inoperative position clear of the said member as the latter moves past the pawl toward its inoperative position.

2. In an article of furniture, in combination, a supporting member mounted for movement between its inoperative and operative positions, and a latch for securing the said member in its operative position comprising a movable locking pawha sliding piece mounted upon the pawl for limited movement relative thereto, means for yieldingly maintaining the sliding piece normally in operative position projecting from the pawl for contact with the sup porting member, the said member-when in operative position in engagement with the pawl being adapted to b ear against thesliding -piece to maintain the same in' retracted position, a movable limiting member adapted to normally project into the path or the supporting member at a position more re'- mote from the inoperative position of the supporting member than its operative position, means for transmitting motion trom the sliding piece of the pawl to the said limiting -member to render the latter in-V operative upon movement of the said piece into retracted position, and a movable releasing device for the locking pawi disposed,

normally so that it projects into the path of a part of the supportingmember but is shielded. from Contact therewith by the limiting member when operative.

3. ln an article of furniture, in combiiia-A losY iat

isa

lA for contact with the supporting member, the said member when in operative position inen agement with the awl being adapted to ear against the sli ing piece to maintain the same in retracted position, a movable limiting member adapted normally to project into.,l the path of the supporting member at a position more remote from the inoperative position of the supporting member than its operative position, means for transmitting motion from the sliding piece of the pawl to the said limiting member "to render the latter inoperative upon movement of the said piece into retracted position, a movable releasing device fort-he locking pawl disposed normally so that it projects into the path of a part of the supporting member but is shielded from contact therewith by the limiting member when member, the said member when 1n operative position in engagement with the pawl being adapted to bear against the sliding piece to maintain the same in retracted position, a movable limiting member adapted normally to project into the path of thev supporting member at a position more remote from the inoperative position of the supporting member than its operative position, means for transmitting motion from the sliding piece of the pawl to the said limiting member to render the latter 'inoperative upon movement of the said piece into retracted position7 a movable releasing device for the locking pawll disposed normally so that it projects into the pathn of a part of the supportingmember but is shielded-\ from contact therewith by the limiting member when operative, and means for locking the sliding piece on the lockastenia ing pawl automatically in retracted position whenmoved into the same While the pawl is in operative position, the last-named locking means being adapted to become released from operative engagement with the sliding piece upon movement of the pavvl into inoperative position. 5. ln an article of furniture, in combination, a supporting member mounted for movement between. its inoperative and operative positions, and a latch vfor securing the said member in its operative position comprising a movable locking pavvl, a sliding piece mounted upon the paWl for limited movement relative thereto, meansfor yieldably maintaining the sliding piece normally in operative position projecting from the pawl for contact with the supporting member, the said member when in operative position in engagement With the pawl being adapted to bear against the sliding piece to maintain the same in retracted position, a movable limiting member adapted normally to project into the path of the supporting member at a position more remote from the inoperative position of the supporting member than its operative position, means for transmitting -motion from the sliding piece of the pawl to the said limiting member to render the latter inoperative upon movement of the said piece into retracted position, a movable releasing device for the locking pawl disposed normally so that it projects into the path of a part of the supporting member but is shielded from Contact therewith by the limiting member when operative, and a second pawl adapted to engage the sliding piece on the irst named paWl automatically upon movement of the said piece into re.

tracted position whilethe first pavvl is in operative position, the said piece being adapted to be moved out of engagement with the second pawl to be released upon movement of the first pawl into inoperative position.

ln witness whereof we have hereunto lset our hands in the presence of two Witnesses.

= ATIHLLE DE VLEESCHOUWEE.

JOHANNES TAGOrlA. Witnesses:

J. D. SALoMoNsoN, W. R. A'rniivsoN. 

